32b6d34fed
In order to link an adjacent node, netdev_upper_dev_link() is used and in order to unlink an adjacent node, netdev_upper_dev_unlink() is used. unlink operation does not fail, but link operation can fail. In order to exchange adjacent nodes, we should unlink an old adjacent node first. then, link a new adjacent node. If link operation is failed, we should link an old adjacent node again. But this link operation can fail too. It eventually breaks the adjacent link relationship. This patch adds an ignore flag into the netdev_adjacent structure. If this flag is set, netdev_upper_dev_link() ignores an old adjacent node for a moment. This patch also adds new functions for other modules. netdev_adjacent_change_prepare() netdev_adjacent_change_commit() netdev_adjacent_change_abort() netdev_adjacent_change_prepare() inserts new device into adjacent list but new device is not allowed to use immediately. If netdev_adjacent_change_prepare() fails, it internally rollbacks adjacent list so that we don't need any other action. netdev_adjacent_change_commit() deletes old device in the adjacent list and allows new device to use. netdev_adjacent_change_abort() rollbacks adjacent list. Signed-off-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.